(a) Technical Field
The present invention relates to a field of automatic filling and packing, and more particularly to a method of packing a liquid composition containing granular constituents and a liquid composition supplying apparatus, adopted in an automatic filling and packing machine to supply and pack, at a high speed, a liquid composition containing regularly or irregularly shaped solids or other granular into a bag formed from a continuously fed packing film having a thermally fusible layer, which is a lamination film in many cases.
(b) Prior Art Statement
When packing in a bag formed from a packing film a liquid composition containing soft or hard granular constituents such as a dressing or hamburger sauce containing minced vegetables or granular spice, pasta sauce containing minced meat, starch syrup containing sesame seeds for fried sweet potato, etc. using an automatic filling and packing machine, a poor seal takes place from time to time. The poor seal is caused by the granular constituents caught between the films at the top and bottom heat seals of the packing bag. More particularly, as the water content of the granular constituents caught between the films at the heat seals is expanded in volume when it is vaporized, the films at the heat seal are not well fused and joined to each other or the films are peeled off. It is the typical conventional measure to make a bottom seal to bottom a packing bag before a liquid composition to be packed is supplied into the bag formed from the packing film, and then a top seal to form the top of the packing bag filled with the composition. The filling of the packing bag with the liquid composition is interrupted during heat sealing at the bottom and top of the packing bag, and the bottom and top seals of the packing bag are formed with such a long distance between them that the liquid composition put into the bag after forming of the bottom seal and rebounded from the bag bottom will not come to a position where the top seal is to be formed.
For intermittent supply of the liquid composition, it is necessary to cease the forming of the bag top until a predetermined amount of the liquid composition is put into the bag. Since the automatic filling and packing machine itself has to be in intermittent operations in this way, the liquid composition containing granular constituents cannot be supplied and packed with so high an efficiency as that in supply and packing of a liquid composition not containing granular constituents.
Also, when a liquid composition containing granular constituents is intermittently supplied and packed, if the liquid viscosity of the composition to be packed is high, the liquid composition will possibly drip unexpectedly after the supply is stopped and the drip be caught between the films at the heat seal of the packing bag, resulting in a poor seal as been described above.
Also, since the distance between the bottom and top of the packing bag is set long as described in the above, the yield of the packing film will be low. In addition, air inevitably sealed in the packing bag during the intermittent supply of the liquid composition, will cause the bag to have a large size and the content of the packing bag to easily be oxidized inside the bag.
It is a primary object of the present invention to overcome the drawbacks of the prior art by providing a method of packing a liquid composition containing granular constituents and a liquid composition supplying apparatus, in which the liquid composition containing granular constituents is separated into a master liquid not containing the granular constituents and a second liquid containing the granular constituents before supply to a bag formed from a packing film, the master liquid is continuously supplied into the bag by the automatic filling and packing machine as in the conventional packing of a liquid composition not containing granular constituents, while the second liquid is intermittently supplied into the master liquid already existing in the bag after a bottom seal is formed and before a top seal is formed, whereby the packing can be done with nearly same efficiency as that of the continuous supply and packing of a liquid.
It is another object of the present invention to provide a method of packing a liquid composition containing granular constituents and a liquid composition supplying apparatus, capable of satisfactorily eliminating the drip of the liquid composition containing granular constituents which will cause a poor sealing.
It is still other object of the present invention to provide a method of packing a liquid composition containing granular constituents and a liquid composition supplying apparatus, capable of improving the yield of the packing film and preventing effectively the content of the packing bag from being oxidized inside the bag.
The method of packing the liquid composition containing granular constituents according to the present invention, is characterized in that during automatic supply and packing of the liquid composition containing granular constituents, a master liquid, not containing the granular constituents, of the liquid composition is continuously supplied into a packing bag formed from a packing film by making bottom and top seals, in this order, on the packing bag with the packing film being stoked and squeezed to remove a part of the master liquid from bag portions where the bottom and top seals are to be formed, and a second liquid, containing the granular constituents, of the liquid composition is intermittently supplied into the packing bag between the bottom and top seals.
The second liquid with granular constituents should preferably be prevented, by the pressure of the master liquid, from dripping.
Also the above object can be attained by providing an apparatus for supplying a liquid composition containing granular constituents into a packing bag formed from a continuously fed packing film by forming longitudinal and lateral seals in this order to the packing film, the apparatus including a main conduit through which only a master liquid, not containing the granular constituents, of the liquid composition is supplied and at least a sub conduit through which a second liquid, containing the granular constituents, of the liquid composition is supplied, the sub conduit being open at the free end thereof in an area where the pressure of the master liquid acts.
To this end, the master liquid of the liquid composition containing granular constituents is continuously supplied into the packing bag as in the conventional packing of the liquid composition while the automatic filling and packing machine is continuously operating, and the second liquid containing the granular constituents is intermittently supplied into the master liquid existing in the packing bag between the bottom and top lateral seals formed by stroking and squeezing the packing bag at portions thereof where the bottom and top seals are to be formed. Thus, the time for supplying and packing the liquid composition can be made approximately equal to that for supply and packing of only the master liquid. Namely, the wait time for the liquid composition supply as in intermittent supply of the whole liquid composition to be packed is made unnecessary, so that the packing efficiency can be improved nearly to that for the conventional packing of ordinary liquid compositions.
Owing to the bottom and top lateral seals formed by stroking and squeezing the packing bag at positions where the seals are to be formed, the packing bag can be formed with the liquid composition containing the granular constituents supplied nearly full in the bag. Therefore, oxidation and loss of flavor of the content of the packing bag can effectively be eliminated, since air remaining in the bag can be purged almost completely or completely from inside the bag.
In addition, since the speed of intermittent supply of the second liquid can be made rather slower than that of the intermittent supply of all the liquid composition by intermittently putting the second liquid of relatively small quantity into the master liquid continuously supplied in the packing bag, the granular constituents in the second liquid can sufficiently be prevented from splashing to where the top seal is to be formed even with the distance between the bottom and top of the packing bag not set long. Thus, the yield of the packing film can be improved drastically and also it is possible to more effectively prevent the content of the packing bag from being oxidized inside the bag.
Further, to prevent the drip of the second liquid containing granular constituents, already intermittently supplied in the packing bag, by the pressure of the master liquid which is always under pressure because it is continuously supplied, no negative-pressure suction or the like has to be used after completion of the intermittent supply of the second liquid, and the unexpected drip of the second liquid can positively be prevented irrespectively of the viscosity of the second liquid. Thus, it is possible to eliminate the likelihood that a part of the granular constituents will be caught between the films at the heat seals of the packing bag.
To accurately make the intermittent supply of a predetermined amount of the second liquid containing granular constituents, the supply pressure for the second liquid should preferably be higher than the pressure of the master liquid since the pressure of the master liquid always acts on the outlet of the second liquid.
More preferably, the second liquid containing granular constituents should be condensed for intermittent supply to the packing bag. Thereby, the time for supplying the second liquid can be reduced to further improve the packing efficiency while a greater amount of the second liquid can be supplied intermittently.
Also, the liquid composition containing granular constituents should preferably be separated into a master liquid not containing the granular constituents and a second liquid containing the granular constituents before the above-mentioned supply is started, whereby an influence on the process for producing the liquid composition can be eliminated.
According to the present invention, the liquid composition supply apparatus includes a main conduit through which only a master liquid, not containing granular constituents, of a liquid composition is supplied into the packing bag formed from the continuously fed packing film, after forming the longitudinal seals, between the longitudinal and lateral seals formed one after another on the packing bag, and at least a sub conduit through which a second liquid, containing the granular constituents, of the liquid composition is supplied and having the free end thereof open in an area where the pressure of the master liquid acts.
Thereby, the pressure of the master liquid can be made to always act on the open end of the sub conduit by continuously supplying the master liquid incessantly as mentioned above to the packing bag. Therefore, it is possible to more positively prevent the second liquid from dripping subsequently by having the pressure of the master liquid act on the open end of the sub conduit in a direction of forcing back the second liquid upon stopping the pressurizing of the second liquid for supply especially when the intermittent supply of the second liquid through the sub conduit is stopped.
The free end of the sub conduit may be open in the middle of the main conduit. The open position of the free end should preferably be as near the open end of the main conduit as possible, which will more facilitate to adjust the timing of intermittent supply of the second liquid.
Otherwise, with the free ends of the main and sub conduits being open inside a common nozzle whose end is drawn, the liquid composition supplying apparatus according to the present invention can be designed more simple and the timing of intermittent supply can be controlled independently of the flow rate of the master liquid, etc.
More preferably, a separator to separate a liquid composition containing granular constituents into a master liquid not containing granular constituents and a second liquid containing the granular constituents should be provided to which the main and sub conduits are to be connected.
These objects and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.